Perfusion type electrophysiological balloon catheter

Abstract

An electrophysiology catheter includes a balloon that can be inflated with perfusion liquid, and the perfusion liquid can be removed therefrom faster than other catheter balloons of similar volumes without damaging electrical components disposed on the balloon. The catheter includes a shaft assembly including a shaft assembly lumen, a choke lumen, and a port connecting the shaft assembly lumen to an interior of the balloon. A guidewire may be disposed in the choked flow lumen to transfer perfusion liquid through the port into the balloon, which inflates the balloon. Upon removal of the guidewire from the choked flow lumen, perfusion liquid may exit the balloon through the port and then exit the catheter via the distal tip of the catheter.

Description

[0001] Cross - Reference to Related Applications

[0002] This patent application claims priority to U.S. Provisional Patent Application No. 63 / 612,709, filed on December 20, 2023, under 35 U.S.C. § 119. This patent application also relates to the subject matter described in U.S. Patent Application No. 15 / 360,966, filed on November 23, 2016 (published as U.S. Patent No. 10,660,700). The entire contents of these applications are hereby incorporated by reference in their entirety. Technical Field

[0003] The subject matter disclosed herein relates to electroablation systems, and more particularly to those ablation systems that include a catheter capable of ablating cardiac tissue. Background Art

[0004] Ablating cardiac tissue can be used to treat arrhythmias. Ablation energy can be delivered to cardiac tissue through structures (such as electrodes) disposed on the distal portion of a catheter. Some catheters have electrodes disposed in or incorporated into a three-dimensional structure (e.g., a wire cage and a balloon). Summary of the Invention

[0005] An electrophysiology catheter includes a balloon that can be inflated with a perfusion fluid and can have the perfusion fluid removed therefrom faster than other catheter balloons of similar volume without damaging the electrical components disposed on the balloon. The electrophysiology catheter includes a shaft assembly that includes a plurality of tubular members having respective walls that together define an interior of the shaft assembly, the interior including a shaft assembly lumen. A first tubular member of the plurality of tubular members includes a first shaft that includes a first shaft wall that forms a first wall of the respective walls, a first shaft proximal portion, a first shaft distal portion, and a first shaft lumen that extends through the first shaft such that the first shaft lumen forms a first portion of the interior of the shaft assembly. A second tubular member of the plurality of tubular members includes a second shaft that includes a second shaft wall that forms a second wall of the respective walls, a second shaft proximal portion, a second shaft distal portion, and a second shaft lumen that extends through the second shaft such that the second shaft lumen forms a second portion of the interior of the shaft assembly. The second shaft is connected to the first shaft such that the first shaft distal portion is disposed distal to the second shaft distal portion and the first shaft proximal portion. A third tubular member of the plurality of tubular members includes a tip that includes a tip wall that forms a third wall of the respective walls, a tip proximal portion, a tip distal portion, and a tip lumen that extends through the tip such that the tip lumen forms a third portion of the interior of the shaft assembly. The tip is connected to the first shaft such that the tip distal portion is disposed distal to the first shaft distal portion and the tip proximal portion.

[0006] A choke region is disposed within the lumen of the shaft assembly. The choke region has a choke lumen, and the width of the choke lumen is less than the width of the portion of the shaft assembly lumen that is proximal to the choke lumen. The balloon defines an internal volume and is connected to the shaft assembly such that the proximal portion of the balloon is connected to the distal portion of the second shaft and the distal portion of the balloon is connected to the distal portion of the first shaft.

[0007] A port is located within the balloon and is configured to pass through a respective wall such that the port defines a proximal passageway between the interior of the shaft assembly and the internal volume of the balloon. The port may be configured to pass through a first shaft wall, wherein a first shaft lumen defines at least a portion of the choke lumen. Alternatively or in addition, the port may also be configured to pass through a distal wall, wherein a portion of the distal lumen defines at least a portion of the choke lumen.

[0008] A guide wire or another catheter (such as a mapping catheter that provides guide wire functionality) may be configured to pass through the shaft assembly lumen. The width of the guide wire or other catheter is equal to or approximately equal to the width of the choke lumen. When the guide wire is disposed within the choke lumen, perfusion fluid provided from a perfusion pump and entering the shaft assembly fills the balloon and pressurizes it into an expanded configuration. When the guide wire is not disposed within the choke lumen, the perfusion fluid contained within the balloon may return to the shaft assembly lumen via at least one of the ports and then exit the electrophysiology catheter through its distal end. Thus, retracting the electrophysiology catheter into the guide catheter lumen of the guiding catheter causes the guiding catheter to compress the balloon and squeeze the fluid contained therein into the shaft assembly and out of the distal end of the electrophysiology catheter. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Although the claims that particularly point out and distinctly claim the subject matter described herein follow the description, it is believed that the subject matter will be better understood from a description of certain examples below, together with the accompanying drawings, in which like reference numerals represent like elements, and in which:

[0010] Figure 1 is a schematic diagram of an invasive medical procedure;

[0011] Figure 2 is a top schematic view of a catheter having a balloon in an inflated state;

[0012] Figure 3 is Figure 2 a perspective schematic view of the distal portion of the catheter of

[0013] Figure 4 is Figure 2 a side schematic view of the distal end of the catheter of

[0014] Figure 5 isFigure 2 Top schematic view of the distal portion of the catheter;

[0015] Figure 6A is Figure 2 Cross-sectional view of the distal portion of the catheter, where the cross-sectional plane X-X is indicated in Figure 5 ;

[0016] Figure 6B is Figure 2 Cross-sectional view of the distal portion of the catheter, where the cross-sectional plane X-X is indicated in Figure 5 ;

[0017] Figure 6C is Figure 2 Cross-sectional view of the distal portion of the catheter, where the cross-sectional plane X-X is indicated in Figure 5 ;

[0018] Figure 7A is Figure 2 Cross-sectional view of the distal portion of the catheter, where the cross-sectional plane X-X is indicated in Figure 5 ;

[0019] Figure 7B is Figure 2 Cross-sectional view of the distal portion of the catheter, where the cross-sectional plane X-X is indicated in Figure 5 ;

[0020] Figure 7C is Figure 2 Cross-sectional view of the distal end portion of the catheter, where the cross-sectional plane X-X is indicated in Figure 5 ;

[0021] Figure 8 is Figure 2 Cross-sectional view of the distal portion of the catheter, where the cross-sectional plane X-X is indicated in Figure 5 ; and

[0022] Figure 8A Top schematic view of the proximal portion of the catheter;

[0023] Figure 9A Depicts Figure 2 the end component of the catheter;

[0024] Figure 9B Depicts Figure 9A the midplane cross-section of the end component to show the seal therein;

[0025] Figure 9C Depicts Figure 9A the midplane cross-section of the end component, where the non-uniform device is arranged to pass through;

[0026] Figure 9D DepictsFigure 9A A midplane cross-section of the distal component, where Figure 9B the seal depicted therein is hidden; and

[0027] Figure 10 depicts a flowchart of a method of depicting the use of Figure 2 a catheter. DETAILED DESCRIPTION

[0028] The following detailed description should be read in conjunction with the accompanying drawings, in which like reference numerals refer to like elements in the different drawings. The drawings (not necessarily to scale) depict selected embodiments and are not intended to limit the scope of the invention. The detailed description illustrates the principles of the invention by way of example and not by way of limitation. This description will clearly enable one skilled in the art to make and use the invention and describes several embodiments, adaptations, variations, alternatives, and uses of the invention, including what is presently believed to be the best mode of carrying out the invention.

[0029] As used herein, the term "about" or "approximately" with respect to any numerical value or range indicates a suitable dimensional tolerance that allows a collection of parts or components to achieve its intended purpose as described herein. More specifically, "about" or "approximately" can refer to a range of values of ±10% of the recited value; for example, "about 90%" can refer to a range of values from 81% to 99%. Additionally, as used herein, the terms "patient," "host," "user," and "subject" refer to any human or animal subject, and are not intended to limit the system or method to human use, although use of the subject invention in a human patient represents a preferred embodiment.

[0030] System Description

[0031] Figure 1 is a schematic illustration of an invasive medical procedure using device 12. The procedure is performed by a medical professional 14, and by way of example, it is assumed that the procedure in the following description includes ablating a portion of the myocardium 16 of the heart of a human patient 18. However, it should be understood that the embodiments disclosed herein are not limited to this particular procedure and may also include substantially any procedure on biological tissue or non-biological material.

[0032] To perform the ablation, the medical professional 14 inserts a probe or guiding catheter 20 into a sheath 21 that has been pre-positioned within the lumen of the patient. The sheath 21 is positioned such that the distal end of the guiding catheter 20 enters the patient's heart. The diagnostic / therapeutic or electrophysiology catheter 24, detailed below with reference to Figure 2 is deployed through the lumen of the guiding catheter 20 and exits from the distal end of the guiding catheter 20.

[0033] As Figure 1As shown, the device 12 is controlled by a system processor 22, which is located in the operation console 24 of the device and is also schematically shown at reference numeral 15. The console 24 includes controls 26 and a screen 28 that can be used by a medical professional 14 to communicate with the processor. Thus, the screen 28 can include a touch screen, and the controls 26 can include, for example, a mouse or a trackball. During the procedure, the processor 22 generally uses any method known in the art to track the position and orientation of the distal end of the guide catheter 20. For example, the processor 22 can use a magnetic tracking method, in which magnetic emitters 25X, 25Y, and 25Z outside the patient 18 generate signals in coils located in the distal end of the guide catheter 20. The system (purchased from Biosense Webster, Inc, Irvine, California) uses such a tracking method.

[0034] The software for the processor 22 can be downloaded electronically to the processor through, for example, a network. Alternatively or in addition, the software can be provided through a non-transitory tangible medium such as an optical, magnetic, or electronic storage medium. The tracking of the distal end of the guide catheter 20 can be displayed on a three-dimensional representation 30 of the heart of the patient 18 on the screen 28. However, it can be displayed in a two-dimensional manner, for example, by fluoroscopy or MRI.

[0035] To operate the device 12, the processor 22 communicates with a memory 32 that has a plurality of modules used by the processor to operate the device. Thus, the memory 32 includes a temperature module 34, an ablation module 36, and a perfusion module 38. The perfusion module 38 can be connected to a pump, allowing the processor to control the pump and thus the flow rate of the perfusion liquid provided to the catheter. The memory 32 generally includes other modules, such as a force module for measuring the force on the distal end of the guide catheter 20, a tracking module for operating the tracking method used by the processor 22, and an electrocardiogram (ECG) module. For the sake of brevity, Figure 1 such other modules are not shown. The modules can include both hardware elements and software elements.

[0036] Figure 2 is a schematic perspective view of an electrophysiology catheter 24, where the balloon 40 is in an inflated configuration. The catheter 24 can include a handle 39 that includes, for example, a knob 42 and controls 44, which can be used to assist in manipulating and positioning the balloon 40. Tubing 46 extends proximally from the handle 39 through which a perfusion liquid such as a saline solution can be pumped. Another catheter or guidewire 48, such as a mapping catheter, can also be passed through the tubing 46 or alternatively through another tubing 50 ( Figure 8A)Insert through the electrophysiology catheter 24. In the case where a single tubing 46 extends proximally from the handle 39, it can bifurcate into two branches 46A and 46B, and this bifurcation can be provided by a Y-shaped connector 52. In this vein, one of the branches 46A and 46B can be connected to a perfusion pump, while the guide wire 48 is arranged to pass through the other branch.

[0037] As Figures 3 to 5 Generally depicted, in the case where the electrophysiology catheter 24 is used to ablate the orifice 11 of the lumen of a pulmonary vein 13, for example, the balloon 40 is supported on the shaft assembly 54. The shaft assembly is tubular, and thus its various components are also tubular. As depicted, the shaft assembly 54 at least includes a first or inner shaft 56 having a first shaft distal portion 58 and a first shaft proximal portion 60, and a second or outer shaft 62 having a second shaft distal portion 64 and a second shaft proximal portion. The shaft assembly 54 may also include a tip 68 having a tip proximal portion 70 and a tip distal portion 72. The shaft assembly 54 may also include a proximal collar 74, a distal collar 76, and a connector 78 having a connector distal portion 84 and a connector proximal portion 86.

[0038] The first shaft 56 and the second shaft 62 are directly or indirectly connected to each other. For example, an indirect connection between the first shaft 56 and the second shaft 62 can be achieved by directly connecting the first shaft proximal portion 60 to the connector distal portion 84 and directly connecting the second shaft distal portion 64 to the connector proximal portion 86. These direct connections can be made using at least one of adhesives and welding.

[0039] Similarly, the balloon 40 of the electrophysiology catheter 24 can be directly or indirectly connected to the second shaft distal portion 64 at its proximal end 80, and directly or indirectly connected to the first shaft distal portion 60 at its distal end 82. For example, an indirect connection can be achieved by connecting the balloon proximal end 80 to the second shaft distal portion 64 via the connector 78, such as by using one or more of the following: adhesives, welding, or compressing the balloon proximal portion 80 onto the proximal collar 74 of the connector 78. Similarly, the balloon distal portion 82 can be connected to the first shaft distal portion 58 via the tip 68, such as by using one or more of the following: adhesives, welding, or compressing the distal end 82 onto the distal collar 76 of the tip 68.

[0040] The balloon 40 of the electrophysiology catheter 24 has a biocompatible material (e.g., made of materials such as polyethylene terephthalate (PET), polyurethane, or The outer wall, surface or membrane 88 of the material formed of plastic). The shaft assembly 54 defines the longitudinal axis 90 of the balloon 40. The balloon 40 is deployed in a collapsed configuration via the lumen 92 of the guide catheter 20 and can be inflated by pressurizing it with perfusion liquid after leaving the distal end, as will be described in detail below. For the balloon 40 intended to be deployed for use at the ostium of the pulmonary vein 11, the balloon is elliptical, e.g., spherical, when inflated. The balloon 40 can have a diameter between about 25 mm and about 35 mm, e.g., about 30 mm. The membrane 88 of the balloon 40 can be formed with perfusion pores or perfusion holes 94 through which fluid (e.g., saline) can be discharged from the interior of the balloon 40 to the outside of the balloon for cooling the tissue ablation site at the ostium.

[0041] The membrane 88 supports and carries a combined electrode and temperature sensing member, each of which is configured as a multi-layer flexible circuit electrode assembly 96. The "flexible circuit electrode assembly" 96 can have many different geometric configurations. In the illustrated embodiment, the flexible circuit electrode assembly 96 has a plurality of radiating bases or strips 98 on which electrodes 99 are disposed. In the embodiment reflected in the figure, one electrode 99 is disposed on each of the bases 98. Thus, for example, if the balloon 40 includes ten bases, the balloon also includes ten electrodes. The bases 98 are evenly distributed around the balloon 40. Each base has a wider proximal portion that tapers to a narrower distal portion. Each base further extends between the proximal end 80 of the balloon and the distal end 82 of the balloon.

[0042] Fluid Management

[0043] After the balloon 40 has been positioned inside the heart, near the ostium of the pulmonary vein 11 or in the ostium of the pulmonary vein 11, the perfusion pump is activated via the perfusion module 36 to provide perfusion liquid, e.g., saline, from the tubing 46 through the electrophysiology catheter 24 and into the internal volume 41 of the balloon 40. The pump can provide perfusion liquid at a first or lower flow rate and a second or higher flow rate. The lower flow rate can be between about 0 ml / min and about 10 ml / min, such as between about 2 ml / min and about 5 ml / min, e.g., about 3.5 ml / min. The higher flow rate is greater than the lower flow rate and can be between about 10 ml / min and 50 ml / min, such as between about 25 ml / min and about 35 ml / min, e.g., about 30 ml / min. Initially, the lower flow rate is provided while the balloon remains in the collapsed configuration. When the flow rate is increased to the higher flow rate, pressure is established in the internal volume 41 of the balloon 40 such that the balloon 40 expands to have the spherical shape depicted in the figure. After the balloon has expanded from the collapsed configuration to the inflated and spherical configuration, the perfusion liquid can emerge from the holes 94 in the form of droplets or jets, as Figure 4 depicted therein.

[0044] When ablation is completed at a particular location, the balloon 40 is moved to another cardiac location or removed from the heart. Both of these operations typically require reducing the flow rate of the perfusion fluid to a smaller flow rate, collapsing the balloon 40, and retracting it into the guiding catheter 20. However, collapsing the balloon 40 and retracting it into the guiding catheter requires expelling a sufficient volume of perfusion fluid from the internal volume 41 of the balloon to avoid damaging the balloon 40 or its electrical components. Typically, the perfusion fluid is expelled from the internal volume 41 by slowly retracting the balloon 40 into the guiding catheter 20 such that the end of the guiding catheter pushes against the membrane 88, thus squeezing the balloon and forcing the perfusion fluid to exit the internal volume 41 through the holes 94. The applicant has determined that when the smaller flow rate is about 5 ml / min, the inflated balloon has a diameter of about 30 mm, and the design of the balloon includes holes 94 of sufficient size and number to cause perfusion fluid jets to emerge from the holes 94 when pumping the perfusion fluid at a larger flow rate between about 25 ml / min and about 35 ml / min. Expelling the perfusion fluid from the internal volume by pressing the perfusion fluid against the end of the guiding catheter while retracting the perfusion fluid into the guiding catheter takes about thirty seconds, and attempts to expel the perfusion fluid more quickly by retracting the balloon 40 into the guiding catheter 20 more quickly may damage the balloon 40 and its electrical components. Since during a given procedure the balloon 40 may need to be retracted into the guiding catheter between about five and about fifteen times (e.g., ten times), the applicant has identified reducing the time taken to expel the perfusion fluid from the internal volume 41 and retract the balloon 40 into the guiding catheter as an opportunity for improving the design and use of the electrophysiology catheter 24. Accordingly, the applicant has conducted research and development efforts based on this opportunity and has proposed the following exemplary solution embodied in the shaft assembly 54.

[0045] For purposes of detailing the small features and internal features of the shaft assembly, Figures 6A to 6C 、 Figures 7A to 7C and Figure 8 depicts a central plane cross-section of the shaft assembly 54 as Figure 5 depicted. This cross-section is parallel to the sheet containing Figure 5 as indicated by the cross-section X-X and contains the axis 90. In Figures 6A to 6C 、 Figures 7A to 7C and Figure 8 the guiding catheter 20, the collar 74, and the collar 76 are hidden, while the balloon 40 is depicted in a truncated form such that its distal portion 82 and its proximal portion 80 remain visible. From Figures 6A to 6C ​​At the beginning, the shaft assembly 54 includes a plurality of tubular components, namely, a first shaft 56, a second shaft 62, a tip 68, and a connector 78 that are connected to each other. Since these components are tubular, each component has an outer wall and an inner cavity. As shown in the figure, the first shaft 56 includes a first shaft wall 55 that defines a first shaft interior 56i including a first shaft inner cavity 57, the second shaft 62 includes a second shaft wall 61 that defines a second shaft interior 62i including a second shaft inner cavity 63, and the tip 68 includes a tip wall 67 that defines a tip interior 68i and a tip inner cavity 69. The first shaft interior, the second shaft interior, and the tip interior together each form a corresponding part of the interior of the shaft assembly, through which the shaft assembly inner cavity 59 passes. In other words, the first shaft wall 55, the second shaft wall 61, and the tip wall 67 define the interior of the shaft assembly 54, while the first shaft inner cavity 57, the second shaft inner cavity 63, and the tip inner cavity 69 include the shaft assembly inner cavity 59 within the shaft assembly 54. As Figure 6B seen, the guide wire 48 can pass completely through the shaft assembly inner cavity 59. Additionally, the first shaft 56 can be completely disposed inside the balloon 40.

[0046] The connection between the first shaft 56 and the second shaft 62 positions the distal portion 58 of the first shaft distally of the distal portion 64 of the second shaft and the proximal portion 60 of the first shaft. The connector 78 can be used to facilitate this connection by inserting the proximal portion 60 of the first shaft into the distal portion of the connector 78 and inserting the distal portion 64 of the second shaft into the proximal portion of the connector 78 and fixing them therein, for example, with glue or epoxy resin. In this way, the first shaft 56 and the second shaft 62 are indirectly connected to each other via their direct connection to the connector 78. Additionally, the proximal portion 80 of the balloon is connected to the distal portion of the connector 78, for example, directly connected by a collar 74.

[0047] Similarly, the connection between the first shaft 56 and the tip 68 positions the distal portion 70 of the tip distally of the distal portion 58 of the first shaft and the proximal portion 72 of the tip. The distal portion 58 of the first shaft is disposed within and attached to the proximal portion 72 of the tip, for example, directly attached thereto with glue or epoxy resin. Additionally, the distal portion 82 of the balloon is connected to the tip 68, for example, directly connected by a collar 76.

[0048] Various ports are also provided to pass through the components of the shaft assembly 54. As Figures 6A to 6CAs depicted, at least one port 102 is arranged to pass through the first shaft wall 55, inside the balloon 40, and two instances are depicted. Thus, port 102 provides a passage between the first shaft lumen 57 and the inside of the balloon 41. Additionally, at least one port 104 is arranged to pass through the second shaft wall 61, and the connector port 106 is arranged to pass through the connector 78 and be aligned with port 104 such that ports 104 and 106 are located in the balloon 40 and together provide a passage between the second shaft lumen 63 and the inside of the balloon 41. Thus, ports 102, 104, and 106 provide a passage for perfusion liquid to pass between the internal volume 41 of the balloon 40 and the shaft assembly lumen 59. Oriented in this way, port 102 can be referred to as the distal port, and port 104 or ports 104 and 106 can be referred to as the proximal port.

[0049] The shaft assembly lumen 59 further includes a flow restriction region 108. As Figures 6A to 6C depicted, the flow restriction region 108 is located in the distal portion 58 of the first shaft. The flow restriction region 108 has a flow restriction lumen 110, which has a flow restriction width W1 that is less than the width W2 of the portion of the shaft assembly lumen 59 located proximal to the flow restriction region 108. As Figures 6A to 6C depicted, the flow restriction lumen 110 thus includes a portion of the first shaft lumen 57 that has a smaller width than the remainder of the first shaft lumen 57. The guide wire 48 should have a width W3 that is equal to or slightly less than the width W1 such that the guide wire 48 can easily pass through the flow restriction lumen 110. W1 can be between about 0.90 mm and about 1.25 mm, for example, about 1.0 mm. W2 can be between 1.0 mm and about 1.75 mm, for example about 1.25 mm, and should be greater than W1. W3 can be between about 0.85 mm and about 0.95 mm, for example 0.91 mm, and should be less than or equal to W1.

[0050] When the guide wire 48 is not disposed in the flow restriction lumen 110, as Figure 6A and Figure 6CAs depicted, the perfusion liquid can flow through at least one of ports 102 and 104 through the lumen 59 of the shaft assembly into volume 41 and also through the flow restriction lumen 110 to exit from tip 68. Since the perfusion liquid can flow out from tip 68, the perfusion liquid cannot maintain the internal pressure in balloon 40 suitable for ablation procedures using electrode 99 even when pumped at a relatively high flow rate (and also at a relatively low flow rate), or cannot generate a perfusion liquid jet through hole 94. However, when guidewire 48 is disposed in flow restriction lumen 110, the perfusion liquid either cannot pass through flow restriction lumen 110 or is substantially restricted from doing so. Thus, when guidewire 48 is disposed in flow restriction lumen 110, the perfusion liquid pumped at a relatively high flow rate can maintain the internal pressure in the balloon suitable for ablation procedures using electrode 99 and can also generate a perfusion liquid jet through hole 94.

[0051] Accordingly, this configuration of shaft assembly 54 can shorten the duration for balloon 40 to collapse from its inflated configuration and retract it into guide catheter 20. That is, when guidewire 48 is disposed in flow restriction lumen 110, after balloon 40 is pressurized to its inflated / spherical configuration by providing perfusion liquid at a relatively high flow rate, the flow rate can be reduced to a relatively low flow rate and guidewire 48 can be displaced proximally, for example, to the Figure 6C position depicted in. From there, retracting balloon 40 into guide catheter 20 causes balloon 40 to contract toward its collapsed configuration, which squeezes the perfusion liquid in internal volume 41 out of port 102 and restricts or prevents any perfusion liquid pumped at a relatively low flow rate from entering internal volume 41 through ports 102 and 104. Instead, the perfusion liquid flows through flow restriction lumen 110 and exits from tip 68.

[0052] Turning to Figures 7A to 7C , another configuration of shaft assembly 54 is depicted. This configuration is similar to the Figures 6A to 6C configuration described, except that: 1) the flow restriction region 108 and the flow restriction lumen 110 are disposed in tip 68; 2) tip 68 includes tip ports 112 located proximal to the flow restriction region 108 (two are depicted therein) and within balloon 40. Thus, in this configuration, at least one of ports 102 and 104 serves as a proximal port proximal to the flow restriction region 108 and tip ports 112, which means that tip ports 112 can also be referred to as distal ports. Similarly, since the flow restriction region 108 is disposed in the distal portion 70 of the tip, the flow restriction lumen 110 includes at least a portion of the tip lumen 69. Additionally, the proximal portion 72 of the tip is directly connected, for example, by glue or epoxy resin to the distal portion of the first shaft.

[0053] Turning to Figure 8 , another configuration of shaft assembly 54 is depicted. This configuration is similar to that described for Figures 6A to 6C except that inFigure 8 In addition to the second shaft lumen 63, a second second shaft lumen 65 is provided. The second second shaft lumen 65 provides a passage for the guide wire 48 and is not connected to a perfusion pump for receiving perfusion fluid. Thus, as Figure 8A seen, two tubes 46 and 50 extend proximally from the handle 39. The tube 46 remains connected to the first second shaft lumen 63 and remains connectable to a perfusion fluid pump, while the tube 50 is connected to the second second shaft lumen 65.

[0054] While the previous description relates to a design in which the occlusion width W1 of the occlusion lumen 110 is selected based on the width of the guide wire 48, which typically has a uniform or nominally uniform cross-section along its length. However, a catheter, particularly a mapping catheter, may have a non-uniform cross-section that is wider along at least one longitudinal portion than along another longitudinal portion. To facilitate the use of non-uniform devices, such as non-uniform catheters or non-uniform guide wires, that will be advanced through the catheter 24, a seal may be incorporated into the tip that is capable of accommodating the movement of the non-uniform device and maintaining a seal against portions of the non-uniform device having different widths, even when the non-uniform device is moved relative to the seal.

[0055] For example, referring to Figures 9A to 9D , the tip 168 may include a seal 170. The seal 170 may be disposed within the occlusion lumen 111, which, as depicted, includes a portion of the tip lumen 169. For example, the tip 168 may include a cavity 176 in which the seal 170 may be placed and attached to the tip 168, for example, by bonding it therein with an adhesive. As depicted, the seal 170 includes a wiper seal, i.e., a tubular seal having a constriction 172 disposed within the lumen 173 of the seal, which lumen defines an aperture 174 having an aperture width W. A non-uniform device 148, including at least one minimum width portion 178 and one maximum width portion 180, is advanced, positioned, and retracted through the seal aperture 174. At least the constriction 172 should be positioned distal to the tip port 112 (the most distal port of the catheter), but the entire seal 170 may be positioned distal to the tip port 112. Of course, if the proximal portion of the seal 170 extends proximal to the tip port 112, the seal 170 should include a port that is aligned with the distal tip port 112 such that fluid may pass between the internal volume 41 of the balloon 24 and the shaft assembly lumen 59.

[0056] When the non-uniform device moves through the aperture 174 of the constriction 172, contact between the seal 170 and the non-uniform device 148 can be maintained. Thus, as long as the non-uniform device 148 and the constriction 172 are in contact with each other, the seal between the seal 170 and the non-uniform device 148 is maintained. However, because the goal of the subject matter presented herein is to enable the user to collapse the balloon 40 more rapidly, a perfect seal is not required as long as fluid flow through the aperture 174 is sufficiently restricted while the non-uniform device 148 is disposed therein to achieve a desired pressure inside the balloon 40 for inflation and to generate a perfusion fluid jet. Accordingly, the width W4 of the aperture 174 can be equal to or slightly greater than the minimum width of the non-uniform device 148, i.e., the width of the minimum width portion 178 of the non-uniform device 148. For a non-uniform device 148 having a minimum width (i.e., the width of the minimum width portion 178), suitable exemplary dimensions include a width of the aperture 174 of from about 0.38 mm to about 0.95 mm, e.g., about 60 mm, with the minimum width ranging between these same dimensions, i.e., between about 0.38 mm and about 0.95 mm, e.g., about 60 mm. In order for portions of the non-uniform device 148 having a width greater than the minimum width of the aperture 174 (which can include the entirety of the non-uniform device, including the minimum width portion 178) to pass through the aperture 174 of the constriction 172, the constriction 172 should be able to flex and bend. Thus, the seal 170 should be made of a material including an elastomer, e.g., medical grade silicone or polyurethane, having a Shore A durometer hardness between about 25 and about 40.

[0057] The shaft assembly 54 can include ports of other configurations that enable pressurization of the balloon 40 when the guide wire 48 is disposed through the flow blocking lumen 110 and then enable the liquid contained in the balloon 40 to easily or rapidly flow out of the balloon 40 into the shaft assembly lumen 59 and out the distal end 68, particularly in response to compressing the balloon 40 against the distal end of the guide catheter 20 while retracting the balloon 40 into the lumen 92 of the guide catheter 20 while the guide wire 48 is not disposed in the flow blocking lumen 110. For example, any number of ports 102, 104, and 112 can be provided, and in some configurations, only one or two of these ports may be sufficient to achieve the design goal. Conversely, additional ports may be required in certain situations. Any design decisions regarding the number and placement of ports should be determined based at least on the perfusion flow rate used, the diameter of the ports, the size of the balloon, and the speed at which the balloon 40 should be collapsed. For example, the diameter of any one of the ports 102, 104, and 112 can be between about 0.4 mm and 0.8 mm, e.g., 0.6 mm.

[0058] With the embodiments shown and described herein, Applicant has devised a method for using an electrophysiology catheter (e.g., catheter 24) and variations thereof, the electrophysiology catheter having a balloon (e.g., balloon 40) disposed on its distal portion, wherein the perfusion liquid in the balloon can be rapidly discharged from the balloon such that the balloon can be rapidly retracted into the guiding catheter without damaging the balloon or any electrical components of the balloon. The method is depicted as method 200 in the Figure 10 flowchart of

[0059] Method 200 begins at step 202, which includes positioning the distal portion of the guiding catheter near a target location in the human heart. At step 204, the distal portion of the electrophysiology catheter including balloon 40 is extended from the guiding catheter, wherein the balloon is in its collapsed configuration. At step 206, perfusion is initiated by starting a perfusion pump with a perfusion module. If the perfusion pump is started before the electrophysiology catheter is extended from the guiding catheter, the pump should be set to a lower flow rate. However, after the balloon is positioned outside the guiding catheter, the perfusion pump is set to a higher flow rate.

[0060] At step 208, the balloon is inflated to its expanded elliptical configuration. Thus, to account for variations where the pump is started while the balloon is in the guiding catheter and pumped at a lower flow rate, step 208 additionally includes step 208a of verifying that the pump is set to provide perfusion liquid at a higher flow rate, and if the pump is not set to provide perfusion liquid at a higher flow rate, setting the pump accordingly. Then, at step 208b, a portion of a guidewire or non-uniform device (e.g., a mapping catheter) is disposed within the flow-blocking lumen. This blocks or restricts the outflow of perfusion liquid from the end of the catheter's shaft assembly. Thus, all or most of the perfusion liquid entering the shaft assembly lumen must enter the internal volume of the balloon via the ports of the shaft assembly. This pressurizes the balloon into its expanded elliptical structure and causes a jet of perfusion liquid to flow out of the holes in the balloon.

[0061] At step 210, ablation therapy can be provided to cardiac tissue by activating an electrode with an ablation module. At step 212, the perfusion pump is set to pump perfusion liquid at a lower flow rate. At step 214, which begins between about 0 seconds and about 5 seconds after step 212 is completed, the guidewire is retracted distally such that no portion of it remains within the flow-blocking lumen.

[0062] At step 216, the electrophysiology catheter is retracted into the guiding catheter such that the end of the guiding catheter compresses the balloon, thus forcing some of the perfusion liquid inside the balloon to flow out via at least the most distal port of the shaft assembly (i.e., such as Figures 6A to 6C port 104 in Figures 7A to 7CThe port 112) in flows back into the inner cavity of the shaft assembly. For the perfusion liquid such as the flow rate and the size of the port used, the perfusion liquid can also flow back into the inner cavity of the shaft assembly via any other port. Therefore, the continuous compression of the balloon caused by retracting the balloon into the guiding catheter causes the perfusion liquid in the balloon to finally flow out of the shaft assembly through the catheter tip. Eventually, the entire balloon is retracted into the guiding catheter, and at this time the balloon has also returned to its collapsed configuration. For a balloon with an inflated spherical configuration having a diameter between about 25 mm and about 35 mm, step 216 can be completed in less than about fifteen seconds (e.g., between about five seconds and about fifteen seconds) after step 214 is completed without damaging the balloon or its electrical component part. At step 218, the medical professional determines whether to provide additional ablation treatment from the balloon. If so, some or all of the foregoing steps starting from step 204 are repeated. If not, at step 220, the method ends by removing the electrophysiological catheter and the guiding catheter from the patient's heart.

[0063] Any example or embodiment described herein may also include various other features in addition to or as alternatives to those described above. The teachings, expressions, embodiments, examples, etc. described herein should not be regarded as independent of each other. With reference to the teachings herein, various suitable ways in which the teachings herein can be combined will be apparent to those skilled in the art.

[0064] Exemplary embodiments of the subject matter contained herein have been shown and described, and further improvements to the methods and systems described herein can be achieved by making appropriate modifications without departing from the scope of the claims. In addition, where the above methods and steps represent specific events occurring in a specific order, it is intended herein that certain specific steps do not necessarily have to be performed in the order described, but can be performed in any order as long as the steps enable the embodiment to achieve its intended purpose. Therefore, if there are variations of the present invention and these variations fall within the scope of the substance of the disclosure or equivalents of the present invention found in the claims, this patent is intended to cover these variations as well. Many such modifications will be apparent to those skilled in the art. For example, the examples, embodiments, geometries, materials, dimensions, ratios, steps, etc. described above are illustrative. Therefore, the claims should not be limited by the specific details of the structures and operations shown in this written description and the drawings.

Claims

1. An electrophysiological catheter, comprising: A shaft assembly, the shaft assembly comprising: a plurality of tubular members having respective walls that together define an interior of the shaft assembly, the interior including a shaft assembly lumen; a first tubular member of the plurality of tubular members comprising a first shaft including a first shaft wall forming a first wall of the respective walls, a first shaft proximal portion, a first shaft distal portion, and a first shaft lumen extending through the first shaft such that the first shaft lumen forms a first portion of the interior of the shaft assembly; a second tubular member of the plurality of tubular members comprising a second shaft including a second shaft wall forming a second wall of the respective wall, a second shaft proximal portion, a second shaft distal portion, and a second shaft lumen extending through the second shaft such that the second shaft lumen forms a second portion of the interior of the shaft assembly, the second shaft being connected to the first shaft such that the first shaft distal portion is disposed distally of the second shaft distal portion and the first shaft proximal portion; and A flow blocking area, the flow blocking area is arranged in the inner cavity of the shaft component, the flow blocking area includes a flow blocking inner cavity, and the flow blocking width of the flow blocking inner cavity is smaller than the width of a portion of the inner cavity of the shaft component located proximal to the flow blocking inner cavity; a balloon defining an interior volume coupled to the shaft assembly such that a proximal portion of the balloon is coupled to the second shaft distal portion and a distal portion of the balloon is coupled to the first shaft distal portion; a proximal port located within the balloon interior and disposed through one of the respective walls such that the proximal port defines a proximal passage between the interior of the shaft assembly and the interior volume of the balloon; and A distal port is located within the balloon and is configured to pass through the one or the other of the corresponding walls such that the distal port defines a proximal passage between the interior of the shaft assembly and the interior volume of the balloon.

2. The electrophysiological catheter according to claim 1, wherein: The portion of the shaft assembly lumen proximal to the flow-blocking lumen has a width between about 1.0 mm and about 1.75 mm.

3. The electrophysiological catheter according to claim 1, wherein: A third tubular member among the plurality of tubular members includes a tip including a tip wall forming a third wall among the corresponding walls, a tip proximal portion, a tip distal portion, and a tip lumen extending through the tip such that the tip lumen forms a third portion of the interior of the shaft assembly, the tip being connected to the first shaft such that the tip distal portion is disposed distally of the first shaft distal portion and the tip proximal portion.

4. The electrophysiological catheter according to claim 3, wherein: The tip proximal portion is directly connected to the first shaft distal portion.

5. The electrophysiological catheter according to claim 3, wherein: The distal port is disposed through the first shaft wall.

6. The electrophysiological catheter according to claim 5, wherein: The first shaft lumen defines at least a portion of the flow-blocking lumen.

7. The electrophysiological catheter according to claim 5, wherein: The distal port is disposed through the terminal wall.

8. The electrophysiological catheter according to claim 3, wherein: The tip lumen defines at least a portion of the flow-blocking lumen.

9. A method of using the electrophysiology catheter according to claim 1, the method comprising: Start the priming pump; allowing fluid from the infusion pump to flow while a portion of the guidewire is disposed in the flow-blocking lumen; inflating the balloon with the liquid so that the balloon has an elliptical configuration; After the operation of inflating the balloon, displacing the guidewire proximally so that the portion of the guidewire is not disposed in the flow-blocking lumen; as well as Following the proximal displacement of the guidewire, the EP catheter is retracted into the guide catheter lumen of the guide catheter.

10. The method according to claim 9, wherein: Retracting the EP catheter into the guide catheter lumen includes compressing the balloon against the distal end of the guide catheter such that at least some of the fluid in the balloon is forced into the distal port and out of the tip distal portion.

11. The method according to claim 10, wherein: Flowing the liquid into the interior volume of the balloon includes pumping the liquid at a volumetric flow rate between about 10 ml / min and about 50 ml / min.

12. The method of claim 11, further comprising reducing the flow rate to a lower flow rate prior to the act of retracting the electrophysiology catheter into the guide catheter lumen.

13. The method according to claim 12, wherein: Retracting the electrophysiology catheter into the guide catheter lumen begins between about 0 seconds and about 5 seconds after reducing the volumetric flow rate.

14. The method according to claim 12, wherein: The elliptical configuration of the balloon is spherical and has a diameter between about 25 mm and about 35 mm, and the operation of fully disposing the balloon within the lumen of the guide catheter is completed in less than about fifteen seconds after the operation of reducing the volumetric flow rate.

15. An electrophysiological catheter, comprising: A shaft assembly, the shaft assembly comprising: a plurality of tubular members having respective walls that together define an interior of the shaft assembly, the interior including a shaft assembly lumen; a first tubular member of the plurality of tubular members comprising a first shaft including a first shaft wall forming a first wall of the respective walls, a first shaft proximal portion, a first shaft distal portion, and a first shaft lumen extending through the first shaft such that the first shaft lumen forms a first portion of the interior of the shaft assembly; a second tubular member of the plurality of tubular members comprising a second shaft including a second shaft wall forming a second wall of the respective wall, a second shaft proximal portion, a second shaft distal portion, and a second shaft lumen extending through the second shaft such that the second shaft lumen forms a second portion of the interior of the shaft assembly, the second shaft being connected to the first shaft such that the first shaft distal portion is disposed distally of the second shaft distal portion and the first shaft proximal portion; and a flow-blocking region disposed in the lumen of the shaft assembly, the flow-blocking region comprising a flow-blocking lumen having a flow-blocking width and a seal disposed in the flow-blocking lumen; a balloon defining an internal volume connected to the shaft assembly such that a proximal portion of the balloon is connected to the second shaft distal portion and a distal portion of the balloon is connected to the first shaft distal portion; a proximal port located within the balloon interior and disposed through one of the respective walls such that the proximal port defines a proximal passage between the interior of the shaft assembly and the interior volume of the balloon; and A distal port is located within the balloon and is configured to pass through the one or the other of the corresponding walls such that the distal port defines a proximal passage between the interior of the shaft assembly and the interior volume of the balloon.

16. The electrophysiological catheter according to claim 15, wherein: The seal is in tubular form and includes a sealing lumen.

17. The electrophysiological catheter of claim 16, wherein: The portion of the shaft assembly lumen proximal to the flow-blocking lumen has a width between about 1.0 mm and about 1.75 mm.

18. The electrophysiological catheter of claim 16, wherein: A constriction in the sealed interior cavity defines an aperture.

19. The electrophysiological catheter of claim 18, wherein: The constriction is disposed distally of the distal port.

20. The electrophysiological catheter of claim 18, wherein: The width of the holes is between about 0.38 mm and about 0.95 mm.

21. The electrophysiological catheter of claim 15, wherein: The seal includes an elastomer having a Shore A durometer hardness of between about 25 and about 40.

22. The electrophysiological catheter of claim 15, wherein: The seal comprises a dust seal.

23. The electrophysiological catheter of claim 22, wherein: The distal port is disposed through the terminal wall.

24. The electrophysiological catheter of claim 15, wherein: A third tubular member among the plurality of tubular members includes a tip including a tip wall forming a third wall among the corresponding walls, a tip proximal portion, a tip distal portion, and a tip lumen extending through the tip such that the tip lumen forms a third portion of the interior of the shaft assembly, the tip being connected to the first shaft such that the tip distal portion is disposed distally of the first shaft distal portion and the tip proximal portion.

25. The electrophysiological catheter of claim 23, wherein: The flow-blocking lumen includes at least a portion of the tip lumen, and the seal is disposed in a portion of the flow-blocking lumen including at least the portion of the tip lumen.

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